Filtering post-Newtonian gravitational waves from coalescing binaries

Gravitational waves from inspiralling binaries are expected to be detected using a data analysis technique known as {\it matched filtering.} This technique is applicable whenever the form of the signal is known accurately. Though we know the form of the signal precisely, we will not know {\it a priori} its parameters. Hence it is essential to filter the raw output through a host of search templates each corresponding to different values of the parameters. The number of search templates needed in detecting the Newtonian waveform characterized by three independent parameters is itself several thousands. With the inclusion of post-Newtonian corrections the inspiral waveform will have four independent parameters and this, it was thought, would lead to an increase in the number of filters by several orders of magnitude---an unfavorable feature since it would drastically slow down data analysis. In this paper I show that by a judicious choice of signal parameters we can work, even when the first post-Newtonian corrections are included, with as many number of parameters as in the Newtonian case. In other words I demonstrate that the effective dimensionality of the signal parameter space does not change when first post-Newtonian corrections are taken into account.Comment: 5 pages, revtex, 2 figures available upon reques

Nucleosynthesis Constraints on Scalar-Tensor Theories of Gravity

We study the cosmological evolution of massless single-field scalar-tensor theories of gravitation from the time before the onset of $e^+e^-$ annihilation and nucleosynthesis up to the present. The cosmological evolution together with the observational bounds on the abundances of the lightest elements (those mostly produced in the early universe) place constraints on the coefficients of the Taylor series expansion of $a(\phi)$, which specifies the coupling of the scalar field to matter and is the only free function in the theory. In the case when $a(\phi)$ has a minimum (i.e., when the theory evolves towards general relativity) these constraints translate into a stronger limit on the Post-Newtonian parameters $\gamma$ and $\beta$ than any other observational test. Moreover, our bounds imply that, even at the epoch of annihilation and nucleosynthesis, the evolution of the universe must be very close to that predicted by general relativity if we do not want to over- or underproduce $^{4}$He. Thus the amount of scalar field contribution to gravity is very small even at such an early epoch.Comment: 15 pages, 2 figures, ReVTeX 3.1, submitted to Phys. Rev. D1

On the Perturbations of Viscous Rotating Newtonian Fluids

The perturbations of weakly-viscous, barotropic, non-self-gravitating, Newtonian rotating fluids are analyzed via a single partial differential equation. The results are then used to find an expression for the viscosity-induced normal-mode complex eigenfrequency shift, with respect to the case of adiabatic perturbations. However, the effects of viscosity are assumed to have been incorporated in the unperturbed (equilibrium) model. This paper is an extension of the normal-mode formalism developed by Ipser & Lindblom for adiabatic pulsations of purely-rotating perfect fluids. The formulas derived are readily applicable to the perturbations of thin and thick accretion disks. We provide explicit expressions for thin disks, employing results from previous relativistic analyses of adiabatic normal modes of oscillation. In this case, we find that viscosity causes the fundamental p- and g- modes to grow while the fundamental c-mode could have either sign of the damping rate.Comment: Accepted for publication by The Astrophysical Journal. 11 pages, no figure

VIRTUAL REALITY GROUND FORCE COMMANDER TRAINER

The complexity of battlespace is guaranteed to increase over time. The problem arising is that with today’s innovative battlefield and the ever-connected environment, our junior officers are receiving more information, data, and feedback than ever before. With this increased amount of information at their fingertips, we expect them to process this information and make these real-world decisions faster and more precisely than before. Suppose we do not train our leaders to properly handle this information and prioritize tasks, and help them to avoid becoming overwhelmed by the multiple tasks they address. In that case, we run the risk of them becoming cognitively overloaded and making bad decisions based on poor judgment or emotions. These impulsive decisions highly increase the chance of mission failure. Today, we are expecting more out of our ground force commanders (GFCs) in their doctrinal skill set, decision making abilities under pressure, and cognitive performance; however, we are failing to adapt and advance our training at the same pace and level that we expect them to perform. If we cannot teach it, how can we expect our operators to perform at this new level in a new environment? The question: How can Special Operations Forces improve cognitive decision processing under stress and prepare GFCs for future conflicts? Our conclusion is that the adoption of advanced training and technology will help to keep SOF GFCs at the leading edge of combat proficiency.Lieutenant Junior Grade, United States NavyLieutenant, United States NavyApproved for public release. Distribution is unlimited

The 67 Hz Feature in the Black Hole Candidate GRS 1915+105 as a Possible ``Diskoseismic'' Mode

The Rossi X-ray Timing Explorer (RXTE) has made feasible for the first time the search for high-frequency (~ 100 Hz) periodic features in black hole candidate (BHC) systems. Such a feature, with a 67 Hz frequency, recently has been discovered in the BHC GRS 1915+105 (Morgan, Remillard, & Greiner). This feature is weak (rms variability ~0.3%-1.6%), stable in frequency (to within ~2 Hz) despite appreciable luminosity fluctuations, and narrow (quality factor Q ~ 20). Several of these properties are what one expects for a ``diskoseismic'' g-mode in an accretion disk about a 10.6 M_sun (nonrotating) - 36.3 M_sun (maximally rotating) black hole (if we are observing the fundamental mode frequency). We explore this possibility by considering the expected luminosity modulation, as well as possible excitation and growth mechanisms---including turbulent excitation, damping, and ``negative'' radiation damping. We conclude that a diskoseismic interpretation of the observations is viable.Comment: 4 Pages, Latex (emulateapj.sty included), to Appear in ApJ Letters, Vol. 477, Final Version with Updated Reference

Bond Repurchases: A Teaching Case

Companies can buy back and retire their own bonds before maturity, resulting in a possible gain or loss on the extinguishment of debt. What would happen if a company repurchased its own bonds before maturity but did not retire them, potentially holding them for resale later before the bonds mature? This case gives students an opportunity to explore how the repurchase of bonds held for resale should be accounted for, including the repurchase transaction, the disposition of any gain or loss, and the possible transaction to resell the bonds later

Ohio\u27s Modern Courts Amendment Must Be Amended: Why and How

A 1968 amendment to the Ohio Constitution granted the Supreme Court of Ohio the authority to promulgate “rules governing practice and procedure” for Ohio courts. The amendment also provided that “[a]ll laws in conflict with such rules shall be of no further force or effect after such rules have taken effect” and that no rule may “abridge, enlarge, or modify any substantive right.” Although the amendment was explicit about automatic repeal of existing laws, it says nothing about whether the General Assembly may legislate on a procedural matter after a court rule takes effect. That silence has caused enduring confusion. Since 1968, the Supreme Court of Ohio has considered dozens of cases in which a court-promulgated rule appears to conflict with a subsequently enacted statute. The court has reached two views on whether later-enacted statutes that conflict with existing court rules are constitutional. One holds that, because the constitution grants rulemaking authority exclusively to the court, the General Assembly has no authority once the court promulgates a procedural rule. It has also held the opposite: the General Assembly may legislate on a procedural matter already addressed in a court rule if the legislature intends to remake that “matter of practice or procedure” into a “substantive right.” These contradictory interpretations cannot both be right, yet each remains controlling precedent in Ohio. Neither of the court’s contradictory rulings rests on a cogent textual analysis of the 1968 amendment. This failing, however, is no reflection on the court. A definitive resolution of the conflicting interpretations is impossible because the sparse language of the amendment simply does not contain enough textual foundation from which to derive a compelling, permanent answer—one way or the other. The authors propose an amendment that would add language to the 1968 amendment. By providing a textual basis for the court’s second interpretive ruling, it would make clear and permanent the legislature’s authority to share in the process of forming court rules. It would align Ohio’s rulemaking process with Congress’s participation in rulemaking for federal courts and with the large majority of states that preserve for their legislatures at least some participation in forming the content of rules of practice and procedure

The 1972 Typhoon Analog Program (Tyfoon-72)

At the time of writing, author Jerry D. Jarrell was a former Operations Officer at the Joint Typhoon Warning Center, Guam, and was then attending the Naval Postgraduate School. Author Richard A. Wagoner was a former Duty Officer at the Joint Typhoon Warning Center, Guam, and was at the time of writing, attending Texas A and M University.TYFOON, an analog program for the prediction of tropical cyclones in the western North Pacific Ocean, has been in operational use at FWC/JTWC Guam since August 1970. A brief review of TYFOON is presented focussing on its concept, operational results and limitations.Modifications to remedy shortcomings and limitations in the original version are discussed. The modified program TYFOON-72 resulted in the reduction of both computer run time and data storage requirements. Testing and development of the modified program using a sample of 131 forecast situations are reported. TYFOON-72 compared favorably with the official JTWC and TYFOON forecasts at 24 and 48 hr and was superior to both at 72 hr.Author Jerry D. Jarrell was a former Operations Officer at the Joint Typhoon Warning Center, Guam. Author Richard A. Wagoner was a former Duty Officer at the Joint Typhoon Warning Center, Guam